Direct purification of tanshinones from Salvia miltiorrhiza Bunge by high‐speed counter‐current chromatography without presaturation of the two‐phase solvent mixture

Abstract

Tanshen, the rhizome of Salvia miltiorrhiza Bunge, is a famous Traditional Chinese Medicine for multiple therapeutic remedies. This work presents the isolation and purification of tanshinone I and tanshinone IIA from the extract of the rhizome of S. miltiorrhiza by using high-speed counter-current chromatography (CCC) without presaturation of the two-phase solvent mixture. The CCC method combines the results of CCC solvent system selection and components analyses of solvent mixture by GC, and thus it is possible to add accurately each individual solvent to prepare single saturated solvent phase without presaturation. The optimum CCC solvent system is a system of hexane-ethyl acetate-ethanol-water (8:2:7:3, v/v), which has been determined by usual solvent system selection and CCC runs. As a result, over 98% pure tanshinone IIA and over 94% pure tanshinone I have been obtained by using less solvent volume. Their structures have been identified by ESI-MS, NMR spectra.

A novel 9×9 map-based solvent selection strategy for targeted counter-current chromatography isolation of natural products

“…However, there are limited solvent systems to be investigated systematically, such as 10 Ito's solvents, 23 Arizona solvent system and 16 solvent systems. Recently, we found that there are more HEMWat systems having some linear characteristics [36][37][38][39] besides the HEMWat table families [11,26,27,29]. It is a little known what the characteristics of these more comprehensive HEMWat systems are.…”

“…In addition, conductor-like screening model [34] and nonrandom two-liquid segment activity coefficient model [35] were established for solvent system selection. Besides these solvent systems in above family tables, we found that there are more hexane-ethyl acetate-methanol-water solvent systems possessing some linear characteristics [36][37][38][39]. However, there are few studies to address other more comprehensive HEMWat solvent systems.…”

“…Co., Ltd., Zhejiang University, Hangzhou, China), a SE-54 (50 m length, 0.32 mm I.D., 1.00 m film thickness) capillary column (Zhongke Kaidi ChemEng. New Technologies Co., Ltd., Lanzhou, China) was used with isocratic temperature 75 • C under the injector temperature 190 • C and the detector temperature 190 • C. All GC details were the same with our previous experiments [37,39]. The organic components of two phases including hexane, ethyl acetate and methanol were analyzed by gas chromatography with flame ionization detector (GC-FID) using tetrahydrofuran as internal standard according to the reported process [39].…”

“…Targeted CCC separation was similar with previous CCC separation process [9,39,40] and all two-phase solvent systems used for CCC were prepared in classical way by mixing solvents in a separatory funnel at room temperature and separating the two phases before use. In short, the upper phase and lower phase of the solvent system with desired volume ratio were firstly pumped simultaneously to fill the column full.…”

“…The partition coefficients (K) for standard and target compounds were determined by HPLC analysis according to previous study [39]. In brief, small amount (1 mg) of the crude sample was dissolved into equal volume (800 L) of aqueous phase (lower phase) and organic phase (upper phase) of the thoroughly equilibrated twophase solvent system in a 2 mL test tube.…”